When the world war began
- When the first world war began
- When the second world war began
- When the world war 2 began
- When the world war 1 began
- When did the first world war began
- When did the second world war began
- When did the world war 2 began
- When did the world war 1 began
- When world war ii began
- When did the world war began
- When did the second world war began in europe
- When did the 2nd world war began
- When did the first world war began in europe
- When did the 1st world war began
- When will the next world war began